| In the field of oil and gas field exploitation,hydrates are easily formed in high temperature and low pressure environments.The formation of hydrates can cause blockage of the pipes to affect the normal operation of the pipes,resulting in a very high risk of the pipes.Therefore,research on hydrate formation in oil-water emulsion systems is imminent.In order to study the formation of hydrate under different water cut conditions,the experiment firstly used Span80 and Tween80 as a emulsifier.The formation of diesel water-in-oil hydrates under high water cut conditions of 30%,40% and 50% was studied.On this basis,the author further added the lower critical micelle concentration SDS solution and polyethylene glycol 400 to Span80 and Tween80 for the formation rate of the original system hydrate in the 40% moisture system,and studied it.Gas storage density of each system.Then,according to the influence of different nonionic surfactants on the formation of hydrate in oil-water emulsion system,non-ionic surfactants such as Span80,Tween80,Span20 and Tween20 were used in diesel water-in-oil emulsion system with water content of 40% and 275 K,7MPa.The hydrate formation experiment was carried out under the conditions.The results show that the hydrate formation rate of the system with higher water content is faster and the gas storage density is larger.The 40% moisture content system has the shortest induction time and the whole hydration reaction takes the shortest time;a certain concentration of nonionic surface activity is added.The diesel oil-in-water emulsion system can promote the growth of hydrates,shorten the hydration reaction time,and has a significant effect on the improvement of gas storage density.Span80 and Tween80 are paired with 1:1 mass ratio to promote the formation of hydrate in emulsionsystem.The effect is most obvious.When the mass fraction is 0.5%,the hydration reaction time is the shortest,and the hydrate storage density is the highest.It is found that the addition of nonionic surfactant will form a stable interface film and interface charge around the water droplets in the emulsion system.The droplets are difficult to get close to each other and polymerize,which maintains the stability of the water-in-oil emulsion system and has great reference value for hydrate storage and transportation research.In addition,considering the characteristics of viscosity and transparency of oil,the formation of hydrate under the oil-in-water system of white oil was studied.In this paper,Span80 and Tween20 were used as anti-polymerization agents at a mass ratio of 1:1 to investigate the formation of methane hydrate in white oil-in-water white oil emulsion.The experiment compared the formation of hydrates in four different oily white oil emulsion systems of 20%,30%,40% and 50%.The change of emulsion chord length before and after hydration reaction was studied,and the mechanism of hydrate slurry formation and coalescence was explained. |
